A piezoelectric flexure element, or bender, generally comprises two relatively thin strips of piezoelectric material either bonded together or with a metal strip therebetween. The bender is typically mounted in a cantilever fashion. Electrodes comprising, for example, metal coatings are disposed on the outer surfaces of the piezoelectric strips. Furthermore, the strips are oppositely polarized so that the application of a voltage between the electrodes causes one of the strips to expand lengthwise while the other one contracts. As a result, the piezoelectric flexure element bends, and the free end thereof is displaced a distance which depends on the degree of bending and, in turn, on the applied voltage. Such piezoelectric benders are useful in, for example, electrical relays and switches.
The most costly part of a piezoelectric bender is the piezoelectric material employed therein. For this reason, the bender material should be used at maximum efficiency. In a piezoelectric relay, for example, the product of bender force and distance moved by the free end is energy. Ideally, the maximum energy from an activated bender is recovered by forcing the bender to be straight when it is in a "blocked" position; i.e. the free end of the bender is prevented from moving freely when a normal force is applied thereto, as, for example, when a contact on the free end of a bender meets another contact in an electrical relay. Typically, however, when a force is applied to a bender by simple cantilever loading, there is a significant curvature of the bender when blocked, which curvature represents unrecovered potential energy.